#include <REGX52.H>
void Delay1ms(unsigned int xms)		//@12.000MHz
{
	unsigned char i, j;
			while(xms--)
			{i = 2;
			j = 239;
			do
			{
				while (--j);
			} while (--i);
		}
}
unsigned char a;
	void main()
	{
		P2=~0X01;
		while(1)
		{	
			
			if(P3_0==0)
			{
				Delay1ms(20);
				while(P3_0==0);
				Delay1ms(20);
				
				a++;
				if(a>=8)
				{a=0;
				
				}
				P2=~(0x80>>a);
				}
				
				
				
				
			}
		
		
		}
	
	
	